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I Patented Dec. 20,1881.

A. MEUHWART MILL FOR GRINDING GRAINJzc.

(N0 Model.)

(No Model.) 2 Sheets-Sheet 2.

A. MEGHWART.

MILL FOR GRINDING GRAIN, &0.

No. 251,124. Patented-Dec. 20,1881.

WiZness es: Invenior: gggiw kfl M UNITED STATES PATENT Orrrcn.

ANDREAS MEGHWAR-T, OF BUDA-PESTH, HUNGARY.

MILL FOR GRINDING GRAIN, 80C.

SPECIFICATION forming part of Letters Patent No. 251,124, dated December20, 1881.

Application filed April 22, 1880. (No model.) Patented inAustria-Hungary March 9, 1876, imBelgium December 31, 1878,

in France March 7, 1879, and in Italy March 25, 1879.

To all whom it may concern:

Be it known that I, ANDREAS MECHWART, of Buda-Pesth, in the Kingdom ofHungary, have invented an Improvement in Mills for Grinding Grain intoMiddlings and Flour, 850., of which the following is a correctdescription.

This invention is set forth in Letters Patent No. 2,904, granted March3, 1876, in Hungary, to Frederich \rVegmann, and obtained in my behalf;and some of the features are in the Austrian patent, March 9, 1876,Belgian patent, December 31, 1878, Italian patent, March 25, 1879, andFrench patent, M arch 7, 187 9, granted to me.

In this mill the grinding is effected between pairs of cylinders havinggrooved surfaces, said cylinders being revolved at different speeds anddelivering the flour or meal into a hopper or receptacle below.

The peculiarity in the present invention consists in the constructionand arrangement of the devices for adjusting and holding the movablecylinder in each pair of cylinders so as to regulate with accuracy theapproach of one cylinder to the other, whereby absolute contact and wearof one cylinder against the other is prevented and in case of any solidobstruction falling into the mill the rollers will yield, or thepressure can be removed instantly by the attendant. I also combine withthis mill an automatic feeding device that supplies to thegrinding-cylinders only the proper amount of grain.

in the drawings, Figure 1 is an elevation with the gearing removed. Fig.2 is a plan with the frame on one side in section at the line as :r,Fig. 1. Fig. 3 is a section of one of the rollers, and Fig. 4 is a planof the two rollers. The dotted lines on one of the rollers indicate thedirection in which the grooves cross each other at the points ofcontact.

The frames a a are of a suitable size and strength to receive the parts,as hereinafter set forth.

The cylinders b bhave shafls thatare in fixed bearings b upon the framesa, and the cylinders c 0 have shafts that are in yielding bearings orjournal-boxes upon the levers (Z (I. These cylinders 0 o are preferablyof chilled cast-iron. The fulcra e of the levers dare comnuts 2' serveto regulate and adjust the movement of the levers outwardly, and preventthe surfaces of the cylinders b and 0 coming into intimate and injuriouscontact. This also allows the miller to regulate with accuracy the chopor fineness of the flour on meal.

The weights h and levers upon the fulcra lact, through the toes it, uponthe lower ends of the respective'levers d to force them outwardly. TheseWeights can be moved along upon the levers, so as to regulate the forcewith which they act in keeping the pairs of grinding-cylinders together,and in case of any obstruction getting into the mill the pressure isthrown off instantly by turning the handle an and revolving the shaftoand its cranks at each side of the machine to raise the weights h by thechains t, that connect the weights and cranks. The material as crushedor ground falls into a bin or hopper, p, and is removed from the samefrom time to time.

Thegrain,seeds,orothermaterialto be ground is placed in the hopper r, atthe bottom of which there are inclined boards to direct the material tothe upper surface of two rollers, s s, that are revolved, and the grainpasses over these rollers out at a narrow mouth that is between thesurface of the roller and a movable slide 1.. By adjusting this slidethe feed may be increased or lessened, and the movement of the rollerprevents the grain becoming clogged. These rollers ssshould be groovedlongitudinally, and the surfaces of the grinding-cylinders are also tobe grooved longitudinally, but ata slight inclination to the axis, so asto act with a shearing or rubbing cut, and this is promoted by the onecylinder in each pair moving faster than the other cylinder.

A cut-off is provided at 25 by lowering which the supply of grain to thecylinders b c is stopped. This dispenses with altering the adjustmentofthe slide t when it is necessary to shut off the supply of grain to thecylinders b 0.

The gearing employed to drive the cylinders may be of any desiredcharacter. The teeth of the gears are, however, by preference, made witha double inclination, or V-shaped, upon the faces of the wheels, toprevent inequality of movement; and the driving-power may be appliedseparately to the respective pairs of cylinders, or to both pairs ofcylinders, from one pulley or wheel.

The grain, as it is delivered by the rollers 8, runs down an incline,17, directly to the grindingcylinders. There are to be covers a abovethe cylinders I) 0, inclosing them from dust and foreign substances, andthe glass applied at w allows the attendant to observe the flow of thegrain as it passes down the incline c.

Crushing-cylinders have before been made with grooves in the surfacesparallel with the axis, and also oblique orinclined; but when inclinedthe grooves in one cylinder were the reverse ofthose in the adjacentcylinder; hence these grooves as the rollers revolved coincided; and arib of one cylinder might pass into or move opposite to a groove of theadjacent cylinder if the two moved at the same speed;

hence there was not any reliable cutting action between the projectingedges. In instances where grinding has. been done by rollers withsaw-teeth ribs these ribs have been inclined in the same direction butone cylinder revolved in the same direction as the other; hence theadjacent surfaces moved in opposite directions and are not adapted togrinding grain or similar material. I make my cylinders of chilledcast-iron, with the grooves in the same direction of inclination; hencethe right-hand side of one roller in which'the inclination of thegrooves is upwardly will be adjacent to the left-hand side of the nextroller in which the inclination of the grooves is downwardly, and saidgrooves will therefore cross each other, and one roller moving fasterthan the other, the difference of speed being at least one to two, forotherwise the cutting of the grain is not perfect, produces a constantcutting action, similar to a number of shears, and the edges on onecylinder cannot pass into the grooves of the adjoining cylinder, becausethey always cross each other at an inclination. As aresult of thisconstruction the grinding is of the most perfect and uniform character,and the working capacity of the machine is greatly increased.

It is to be understood that the pairs of rollers being geared togetherby gears of difierent sizes insures the proper relative speeds, and theadjacent surfaces of the rollers are moving in the same directions.

In this application I do not make any claim to the hopper and rollerfeed with an adjustable gate and an independent closing-gate, as thesame is shown in my English Patent No. 563 of 1878, and claimed in aprior application made by me for a patent in the United States.

I claim as my invention-- 1. In combination with the pairsofgrindingcylinders, the levers d, fulcrum plates 0, passing intomortises in the levers, the adjustingboltsf, passing from the framethrough the levers, the weighted levers 7t 7t, and lifting device,snbstantially as set forth.

2. In a mill for grinding grain or other material, a pair of chilledcast-iron cylinders, the surfaces of which are obliquely grooved in thesame direction, in combination with mechanism for revolving both rollersat different speeds, substantially as set forth.

3. In a mill for grinding, the combination, with the rollers and thelevers carrying one roller, of screw-bolts secured to the frame of themill, and a nut applied to each screw and bearing against the lever,substantially as and for the purposes set forth.

Signed by me this 24th day of March, A. D. 1880.

ANDREAS MEOHWART.

Witnesses:

SZULANYI LoP'rI, BEIKE BERNHARD.

